Most leaks here are found by the water bill rather than by eye, because slab construction and wall cavities hide them until damage is done.
Confirm it in one minute
Shut off every fixture and watch the water meter. If it still moves, water is going somewhere. That single test tells you whether to worry.
Found without opening walls
Acoustic listening, pressure isolation and thermal imaging locate the failure before anything is cut. That matters especially in older Park Circle houses with plaster walls, where exploratory demolition is both expensive and destructive to finishes worth keeping.
Where they turn up
In pre-war homes, at corroded galvanised sections and previously patched joints. In newer builds, at connectors and fittings rather than in the pipe itself. Two different housing stocks, two different failure patterns, same detection approach.
Why waiting is the expensive option
A slow leak inside a wall stops being a plumbing problem and becomes flooring, cabinetry, drywall and eventually mould remediation. The plumbing repair is almost always the cheapest part of a leak found late.